1. Field of Invention
The present invention relates to a circuit interface device, and more particularly to a thin circuit interface device having a reduced length.
2. Related Art
A Universal Serial Bus (USB) is a standard computer connection interface, which unifies the connectors of various computer peripherals. For example, the communication interface, printer interface, display output, audio output and input devices, and storage equipment (such as an external portable hard disk) all use the USB interface specification. With the characteristics of Plug-and-Play and Hot Swap, the computer peripherals having the USB can be connected or detached at any time in a state that an operating system is booted and runs normally without shutting down or restarting the power supply of a computer host.
Early peripherals applying the USB are portable peripherals such as the portable disk, multimedia player (MP3), recorder pen or wireless receiver, in which a USB connector is soldered onto a circuit board, relevant electronic elements (such as the chips, flash memory, and wireless transmitter) are disposed on the circuit board, and a plastic housing completely covers the circuit board. In use, it is only necessary to insert the USB connector exposed out of one end of the plastic housing into a corresponding socket of the computer host to perform the operation of transmitting relevant signals.
However, at present, the volume of the portable peripherals is required to be light, thin, short, and small, such that users can take the peripherals conveniently. In the structural design described above, as the USB connector is soldered onto the circuit board, the overall length of a portable peripheral may increase due to the parallel design of the connector and the circuit board. Furthermore, when the plastic housing covers the circuit board, in order to accommodate the height of the electronic elements on the circuit board, it is necessary to raise the height of the accommodation space of the plastic housing, thereby causing the increase of the overall thickness of the portable peripheral.
In order to eliminate the above defects, related industries have also brought forward a number of innovations. For example, U.S. Pat. No. 7,165,998 disclosed an improved structure of a USB application apparatus, the design concept of which is to achieve the efficacy of reducing the overall length of the USB application apparatus by using a two-layer circuit board. However, it also brought about a problem on the other hand. The electrical connection contacts of the USB application apparatus are directly disposed on the circuit board so as to be directly electrically connected to the USB socket of the computer through the circuit board; however, since the circuit board is assembled in the housing layer and no support structure is provided below the circuit board, the circuit board may be suspended, and the USB application apparatus cannot be firmly disposed into the socket. Therefore, in U.S. Pat. No. 7,165,998, a support construction and a front protective layer are designed to support the circuit board, and a housing layer is required to cover the connector. However, the assembly of the circuit board, the support construction, and the front protective layer of the prior art still cannot meet the structural strength requirements.
Although the above conventional USB application apparatus reduces the entire volume through the design of the two-layer circuit board, so as to shorten the overall length thereof. However, since the USB application apparatus uses a plurality of elements to support the circuit board, and the structure is quite complicated, the manufacture and processing is very difficult. Further, if the support construction and the front protective layer are assembled in the housing layer through gluing, although the effect of compact bonding is achieved, the assembly needs more work hours and labors, making the assembly process more complicated. Additionally, since the USB application apparatus is compactly bonded through gluing, the USB application apparatus cannot be disassembled freely, and if the housing layer is detached, damage to the USB application apparatus is generated, resulting in that the USB application apparatus cannot be used, and causing a heavy burden on the maintenance.
Additionally, Logitech develops a USB peripheral with a product model V550 Nano. This structure mainly uses the USB peripheral as a receiver of a wireless peripheral input device. The receiver of Logitech has a two-layer circuit board, uses two plastic pieces to clip one end of the two-layer circuit board, and uses a metal housing to cover the exposed two-layer circuit board, so as to constitute a receiver with an integrated profile. In such a manner, the volume of the receiver is reduced to the length of a common USB plug.
However, the receiver developed by Logitech uses plastic pieces and the metal housing to completely cover the circuit board, such that the thickness of the receiver cannot be made thinner, and the receiver cannot match different external designs, for example, cannot use different materials and colors to provide an appearance with a better sense of design according to the market demands. Therefore, it is a problem that needs to be solved urgently for persons in related fields to make the volume of the USB peripheral thinner and have the efficacy of high structural strength at the same time.